Hypoparathyroidism and reversible dilated cardiomyopathy.

Sir,

Dilated cardiomyopathy with left ventricular systolic dysfunction can be reversible in a wide variety of conditions. Metabolic conditions like hypoparathyroidism can be associated with left ventricular systolic dysfunction. We hereby report a case of hypoparathyroidism with severe hypocalcemia, intracranial calcification, psychosis, and reversible dilated cardiomyopathy.

A 70-year-old female presented to the Emergency Department with generalized tonic-clonic seizures. The patient had paresthesia in her distal extremities for two months, altered sensorium for one month, exertional breathlessness, cough for one week, and three episodes of seizures in two days, before her admission to the hospital. She was not a diabetic or hypertensive. On admission, the patient was drowsy, disoriented, and restless. Her vital signs were BP 110 / 80 mm Hg, pulse rate 100 beats per minute, respiratory rate 22 breaths per minute, and temperature 36.8°C. On physical examination, the patient was obese. Chvostek's sign and Trousseau's sign were positive. Fundus examination was normal. Cardiovascular system examination revealed the presence of left ventricular S3. On respiratory system examination, bilateral basal crepitations with rhonchi were present. Laboratory tests showed serum total calcium 3.4 mg / dl (normal 8.8-10.8 mg/dl) and serum phosphate 8.8 mg / dl (normal 2.5-5 mg / dl). Complete hemogram, renal parameters, liver function tests, including serum albumin (4.5 gm / dl), serum electrolytes (sodium, potassium, magnesium), serum ceruloplasmin, and urine examination were within normal limits. The serum parathormone (PTH) level was 2.5 pg/ml (normal 14 - 71 pg/ml). A low serum calcium, high serum phosphate and low PTH level were all consistent with the diagnosis of hypoparathyroidism. There was no history of thyroid surgery or drug intake. A computed tomography scan of the head [Figures 1 and 2] revealed bilateral symmetrical calcification in the basal ganglia and dentate nucleus, which was compatible with the finding of chronic hypoparathyroidism. The chest x-ray showed cardiomegaly. The echocardiogram (ECG) [Figure 3] showed normal sinus rhythm, left axis deviation, and prolonged QT interval (0.55 s). Echocardiography revealed global hypokinesia with mild dilatation of the left ventricle, mild mitral regurgitation, mild aortic regurgitation, trivial tricuspid regurgitation, and left ventricular systolic and diastolic dysfunction, with an ejection fraction of 25%. A final diagnosis of Idiopathic Hypoparathyroidism with intracranial calcification, severe hypocalcemia, psychosis, and dilated cardiomyopathy with congestive cardiac failure, was made. The patient was treated with intravenous calcium gluconate, oral vitamin D, anti-epileptics, and anti psychotics. The patient's condition improved with treatment. Normocalcemia was achieved in three days with a normalized QT interval. The patient was seizure-free, and the breathlessness subsided in two weeks after normalization of the calcium levels. Repeat Echo done at one month of follow-up showed improvement in the left ventricular dimensions and functions (ejection fraction — 52%).

Figure 1

Bilateral dentate nuclei calcification

Figure 2

Bilateral basal ganglia calcification

Figure 3

Echocardiogram Showing QT prolongation

Dilated cardiomyopathy with left ventricular systolic dysfunction can be reversible in a variety of conditions like peripartum cardiomyopathy, alcoholism, and hypothyroidism. Hypoparathyrodism with hypocalcemia is another important condition that can result in reversible dilated cardiomyopathy.[1] Reports of heart failure secondary to hypocalcemia are rather rare.[2] Cardiac manifestations of hypocalcemia include prolongation of the QT interval, ventricular arrhythmias, refractory life-threatening hypotension, and dilated cardiomyopathy.[3] Calcium plays a crucial role in regulating the contraction and relaxation phases of the cardiac cycle. Hypocalcemia leads to decreased myocardial contractility, which may present as heart failure. The heart failure in hypocalcemia is refractory to diuretics and digitalis, but rapidly responds to restoration of calcium levels in the blood.[4]

To conclude, hypoparathyroidism with severe hypocalcemia is an important cause of reversible dilated cardiomyopathy and heart failure, which responds to treatment with calcium. Lack of awareness of this etiology can lead to inappropriate therapy of cardiac failure, with loop diuretics, leading to worsening of hypocalcemia with life-threatening complications.